Hydraulic performance of Molasadra Spillway Dams in Small scale model

One of the ancient hydraulic structure that mankind make it’s in the past until now is spillway. This structure use for regulator and change the water direction in the rivers. So that this structure must be a stable structure and have good hydraulic performance. The aim of research was simulation Molasadra spillway dam with laboratory scale 1:40 height and its performance analyzed using different discharge. The result shown that discharge coefficient have average value 2.1. Meanwhile result of cavitation index indicated have degradation trend and in the large than 1000 (m3/s) discharge, cavitation index reached to critical value with additive trend. Cavitation index in the range of discharge that used in this investigation permanently is more than critical value but with increase discharge the cavitation phenomena is occurred in the end way of the spill way. Minimize and maximize pressure take placed for large discharge respectively in section 4, 9 and 10.